Summation
Ok, let's sum this all up.
The shift lever or twist grip on the left hand side of your handlebar shifts the front derailleur allowing you to choose one of three ranges to ride in. The one on the right shifts the rear derailleur allowing you to make small changes within each range.
If you feel like you're pedaling too hard, use the right hand shifter to switch to an easier gear (like from 7 down to 3 on your shift lever indicator). If you feel like the pedaling is too easy or you're pedaling too fast, use the right hand shifter to switch to an harder gear (like from 4 up to 8).
If you're riding in a hilly area, use the shifter on the left hand side to switch to the smaller (inside) chainring on your crank (position 1 on your shift lever indicator). If you're riding on a smooth flat surface and at a higher speed, use the left hand shifter to switch to the larger (outside) chainring (position number 3). For normal riding shift to the middle chainring (position number 2).
That's about all there is to it. Enjoy your ride. Article - Gearing - Roberts Cycle

I know this is general but it explains what you are trying to do with your gears when you ride a bike on a everyday basis. Notice it does not mention gear ratio,number of teeth, etc. It just mentions how you change gears with the shifters for each hand and situation. When I asked a question a couple of months a go about this and I used similar numbers to ask my question. I was treated with ridicule like I did not understand what I was saying. Here is article that summarizes using the same numbers I was. My point of making this thread is when someone is asking a question there is no need to give complicated answers when simple direct ones will do.

Makes sense to me. I would only add that there is a fair amount of overlap between the ranges, so you can achieve the same "gear" with different combinations.

I think what we have here, is a failure to communicate.

I've been cycling for half a century and when someone says shift from 7 to 3, well, it just doesn't make much sense to me. If they say shifted from 60 inch gear to 72 inch gear, I get it.

But then again I ride a traditional 2x5 10 speed.

I've been cycling almost as long, and have no idea what my gear inches are. But since I am only a roadie on 700c wheels, I think in chainring x cog combinations. 39 x 25 for the steep uphills, and 53 X 12 down the other side.

Just get on the bike and ride. Shifting and being in the correct gear combination will become second nature after a short while. Have fun.

Who has "shift lever indicators?" I've never ridden a bike with them, unless you count the Sturmey Archer 3 speed hub on the bike I rode as a kid. As a result there is nothing simple about the answer provided.

And what's the point of this thread anyway? It's an answer looking for a question.

Basic gearing.
1st gear, it's all right.
2nd gear, I'll lean right.
3rd gear hang on tight.
Faster, faster.

This.
And anyone that feels the need to grossly over complicate it by means of mathematics is OCD or just a fool imo

One of us is old!

Like the old joke goes "My fixed gear has three gears; Sitting, standing and pushing."

I'm not sure what is so simple or direct about the 'answer' you quoted. Articulate? Absolutely, but nothing simple about it. A simple answer would be more like "the left shifter is for big changes and the right shifter is for little changes" I can understand why you may feel that people aren't taking you seriously. It's a "much ado about nothing" thing IMHO. but what matters to me may not matter to you either.

A Guns-N-Roses fan?

I think you need to spend a night in the box.

Basic Gear:

Touche!
I had forgotten where this originally came from... Evidently ol' Axl Rose just stole it from the movie.
Thanks for setting me straight!

Ding Ding WINNER
Sturmey Archer is the only gear you need.

Gear numbering is not consistent.

Neither, now, is shifting direction with SRAM twisties. I replaced the set on my wife's bike two years ago. The old set was a mirror left to right and thus worked in opposite directions, like shifters always have, and the left had three positions. The new one was the same basic unit left and right and thus they both got easier or harder in the same direction, and it had about twelve clicks to permit trim.

Basic Gearing

For me, there is a synergistic, and intutitive relationship among gears, cadence and exertion. I previously posted about cadence:

...and gears are changed to maintain effort level. FWIW

So nobody even mentions cross-chaining? My 2x6 bike won't let me get away with it. The chain rubs and slips off gears. Some people's bikes don't do those things, but the gears may still be suffering premature wear.

I have down-tube levers on that bike, and I've learned to translate lever positions into gear numbers. (Sometimes, though, I still glance between my feet to see where things are.) If it's not cross-chained, the bike is silky smooth. Happy bike = happy rider.

Besides cross-chaining, I have posted about this disaster, which I think is a different phenomenon.

I too look down to see which of the front cogs I am riding. A nice benefit of my training program as described above is that I am riding much more on the larger cog, as increased exertion, as well as evening out the wear between the two cogs.

I had a downtube shifter on my Bridgestone RB-1 that was totalled in a crash about three years ago. Even now though on my replacement carbon fiber bike with trigger shifters, I occasionally reach down to shift as if the downtube levers were there. I liken it to a ”phantom itch” experienced by amputees; my bike was literally torn away from me.

When I was new to cycling, my friends put me on a bike with a computer that showed cadence. ( How many times your pedals make a complete rotation in a minute.) I believe they told me to adjust the gears so I was between 80-95. I never paid attention to what gear I was in and after that it becomes a feeling. Hope this helps.

Boy, do I know the phantom itch! I move between the downtube-shifter bike, an mtb with lever upshift and trigger downshift, another mtb with twist shifters, and a fixie that often has me wishing I could downshift. For more variety, I can try my wife's revised Dunelt with Nexus IGH, similar to a Sturmey-Archer 3-speed but with twist shift. All of this is my way of fighting Alzheimer's.

We're doomed. A few thousand years on the planet and we still can't communicate. Here's one reason why.

The gears (well, we call them gears, they are actually sprockets) on the front of the bike are never referred to as gears but as "chainrings", though they might more accurately be described as disks. The gears on the back of the bike are called gears, not rings or disks and never sprokets. There are several of them and as a group they are referred to as a cassette. There may be a couple gears, err, chainrings up front too, but they are not called a cassette. No group of gears is called a "group set", that is something else (don't ask).

It's OK to call cogs "teeth" if they are on gears, sprockets or chainrings. But the ratio of cogs between gears is always a gear ratio, never a cog, tooth or even sprocket ratio.

Oh, and that wheel on the back with all the gears , err sprockets on it that must be set in motion by the gears, err chainrings up front is called the "free wheel". Though only if it is not a free hub. The wheel on the front of the bike that turns freely in either direction is not called the free wheel, the hub does not enter into it.

(Edit: I've been corrected. It's worse than I thought (:-/

Pardon my confusion, I'm just listening to Toad the Wet Chainring )

A nice Saturday morning smile! (Shakin' the bush, Boss)

It's only a freewheel if it's not a freehub. And my trash-found mtb came with two free wheels, a frame, and other junk.